418 PROFESSOR OWEN ON MACROPUS. 
1853, p. 349) in Prof. Flower’s ‘Introduction to the Osteology of the Mammalia,’ 
12mo, 1870, p. 209. 
For the purpose of paleontological comparison, however, there is the same need of 
illustrations of the osteology of existing species of Macropodide as led to my submitting 
to the Zoological Society those of the Phascolomyide, which they have done me the 
honour to publish in the eighth volume of their useful and valuable ‘Transactions.’ 
To illustrate the characters of the bones in the larger Kangaroos, I have selected 
those of a species of which I am not aware of any figures having been previously given, 
viz. of the great Rufous Wallaroo (Macropus rufus, Desm.', M. laniger, Gaimard* and 
Gould, subsequently referred by the latter eminent explorer of the natural history of 
Australia to his subgenus Osphranter’). 
§ 2. The Skull. 
I may premise that the skull in Kangaroos (Macropodide, Ow. *) is characterized by 
the great length of the diastema, or toothless tract, between the molars and incisors in 
both jaws. A minute rudiment of a canine, or a minute depression where such 
rudiments may have been lodged, is present in some small kinds of Kangaroo, but is 
inconstant in them. 
The skull (Plate LX XIV.) is long, through the extension of the facial or maxillary 
part in front of the orbits (fig. 1, 0); and these cavities, interposed between the facial 
and cerebral part, are large; they widely communicate, as in the rest of the order, with 
the temporal fossze (ib. 7). 
The paroccipital (ib. figs. 1 & 4, 4) and masseteric (ib. 21,2) processes are produced 
downwards—the former to an extreme degree, to which Phascolarctos, perhaps, affords 
the nearest approach in the marsupial order. 
A sagittal crest may be indicated in old males of some of the larger Kangaroos, but 
is never elevated. The zygomatic arch is deep, with the malar (26) element, suspended 
between the maxillary (21) and squamosal (27) piers. The malar contributes a small 
but definite share (ib. fig. 3, 262) to the outer part of the joint for the mandible, the 
entire articular surface (277) being subquadrate, feebly convex transversely, partially 
1<«Mammalogie,’ Supplément, p. 541 (1822). 
* Bulletin des Sciences par la Société Philomatique (1823), p. 138. 
> «Mammals of Australia,’ fol. part v. 
4 Not the Macropide of J. E. Gray, nor the Macropodide of Waterhouse. The former term, like the Didel- 
phide of De Blainville, is equivalent to the ordinal term “ Marsupialia,” see ‘Catalogue of the Bones of Mam- 
malia in the collection of the British Museum,’ 8vyo, 1862, pp. 119-140. ‘The latter term includes the Potoroos 
(Hypsiprymnide) with the Kangaroos. The species, however, which haye the dental formula ?. =, c oo» 
Pp. ae m. = manifest, in the series of extinct with recent forms, so many generic modifications, that a name 
for the canineless family of Poéphaga is requisite. 
